We have established a collaboration to evaluate clinically and to collect biospecimens from persons living with HIV. In a cross-sectional manner, we have collected biospecimens from individuals prior to the initiation of antiretroviral therapy as well as individuals on antiretroviral therapy. We will continue to collect biospecimens from individuals who have initiated antiretroviral therapy in order to monitor the human microbiome as the immune system is restored and as viral load is controlled.